Centering labyrinth seal

ABSTRACT

A centering labyrinth seal for detachably connecting two parts such as cylinder and cylinder head with annular grooves in the surfaces along which the two parts are to be interconnected, said seal including an annular core member having connected thereto radially arranged annular webs with elastically or plastically and elastically deformable sealing lips adapted to engage wall portions of said grooves and to follow axial and radial deformations thereof.

United States Patent Fischer [541 CENTERING LABYRINTH SEAL [72]Inventor: Hans Fischer, Urbanstrasse 54, D 85 Numberg, Germany [22]Filed: July 28, 1970 211 Appl. No.: 58,933

[30] Foreign Application Priority Data Aug. 1, 1969 Germany ..P 19 39195.8

[52] US. Cl. ..277/53, 277/169, 277/171, 277/236 [51] Int. Cl. ..Fl6j15/48, Fl6I 19/00 [58] Field of Search.....277/l7l, 206.1, 169, 236, 53,277/209, 168, 2H

[56] References Cited UNITED STATES PATENTS 2,898,000 8/ I959 Hanny..277/236 X 1 Aug.8, 1972 FOREIGN PATENTS OR APPLICATIONS l,279,545ll/I96l Primary ExaminerSamuel B. Rothberg Attorney-Walter Becker [57]ABSTRACT A centering labyrinth seal for detachably connecting two partssuch as cylinder and cylinder head with annular grooves in the surfacesalong which the two parts are to be interconnected, said seal includingan annular core member having connected thereto radially arrangedannular webs with'elastically or plastically and elastically deformablesealing lips adapted to engage wall portions of said grooves and tofollow axial and radial deformations thereof.

8 Claims, 7 Drawing Figures France ..277/180 CENTERING LABYRINTH SEALThe present invention relates to a centering labyrinth seal fordetachably connecting cylindrical pipes or pipes with closing covers,especially cylinders and cylinder heads of piston-prime movers, forvarying pressure and temperature of gaseous media.

German Patent No. 1,180,999 discloses a cylinder head seal forreciprocable piston internal combustion engines which is provided withlabyrinths. Such labyrinth seal consists of a sealing ring of Y-shapedor double Y-shaped cross-section which is adapted to be inserted into anannular groove of the cylinder and which is spread between the bottom ofthe groove and the bottom side of the cylinder head and has one or twoarms which point toward the pressure chamber and by a preload or by thepressure in the cylinder are pressed against the sealing surfaces. Thearms have a continuous even wall thickness and wide roundednondeforrnable ends which merely engage the sealing surface but do notadapt to any unevenness of the sealing surfaces. Therefore, a precisemachining of the sealing surfaces is imperative. Inasmuch as the sealingsurface on the cylinder head side is located in the same plane as thesupporting surface of the cylinder head, the sealing rings have thetendency, in view of pressure and temperature variations, easily toblow, particular inasmuch as together with the bottom side of thecylinder head they form only one labyrinth chamber. Sealing arrangementsof this type, therefore, are not suitable for high and variablepressures and temperatures. Furthermore, a centering of the parts to beinterconnected is lacking.

German Patent 832,520 describes a cylinder head seal for high pressuresand temperatures which is of a substantially rectangular cross-sectionand is likewise insertable into an annular groove of the cylinder. Atthat surface which faces the cylinder head, the sealing ring has two ormore sharp sealing edges which are directed perpendicularly toward thebottom side of the cylinder head and by means of which labyrinthchambers are formed. That surface which faces the cylinder or the bottomof the groove has a substantially plane engagement with or is pressed bymeans of a sharp edge into the bottom of the groove. In this instance nolabyrinth chambers are provided nor can they be provided in view of thesmall engaging surface. Moreover, the sealing ring requires considerablewidth and in view of the perpendicular sealing edges requires a highpressure to be exerted upon the parts to be interconnected. Whendisengaging the connection, in view of the sealing edges pressed intothe groove bottom, a postmachining of the annular grooves becomesnecessary. A simultaneous centering of the parts to be interconnected islikewise lacking.

It is, therefore, an object of the present invention to provide adetachable labyrinth seal for high and variable pressures andtemperatures of gaseous media which will simultaneously bring about acentering of the two parts to be interconnected and with a surface assmall as possible will permit the provision of as great a number oflabyrinth chambers as possible without requiring an increase in thepressure to be exerted upon the two parts to be connected to each other.

It is another object of this invention to provide a labyrinth seal asset forth in the preceding paragraph,

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings, in which:

FIGS. 1, 3 and 5 respectively illustrate on an enlarged scale differentcross-sectional shapes of the sealing ring according to the inventionand different annular grooves.

FIGS. 2, 4 and 6 respectively illustrate the sealing rings of FIGS. 1, 3and 5 in installed condition.

FIG. 7 shows by way of example a seal according to the invention forsealing two interconnected pipe sections.

The labyrinth seal according to the present invention is characterizedprimarily in that a profiled sealing ring at the joint of the parts tobe connected is insertable partly into one part and partly into theother part of the two parts to be interconnected, and is furthermorecharacterized in that the profile of the sealing ring. is such that atits circumference labyrinth chambers are formed by radial webs startingfrom its center, which webs at the engaging surfaces of the annulargrooves form sealing lips and elastically or plastically and elasticallyfollow axial and radial deformations of the two parts as they may becaused by pressure and temperature variations.

The annular grooves in the parts to be interconnected may have differentcross-sectional shapes. The cross-sectional shape of a semicircle or arectangular triangle the hypotenuse of which coincides with the plane ofthe joint is preferred.

According to a further development of the invention, each of the webs isprovided with two sealing lips .extending in opposite direction withregard to each other and at an acute angle extending toward the engagingsurfaces of the annular grooves whereby between said sealing lips afurther labyrinth chamber is formed.

In view of the elastic webs and sealing lips, also any possible minorlateral offsetting of the annular grooves with regard to each other iscompensated for while a centering is nevertheless effected. Similarly, aslight spring of the two parts to be interconnected will be compensatedfor.

Referring now to the drawings in detail, FIGS. 1 and 2 show a sealingring 1 and two parts 2 and 3 to be connected to each other. The parts 2and 3 each are provided with semicircular annular grooves 4 and 5 of thesame diameter. The sealing ring 1 has four webs 6 which extend from thecenter of the sealing ring radially outwardly. Each of. said webs 6 isprovided with two slender and elastic sealing lips 7, 8 which extend inopposite direction with regard to each other and which form an acuteangle with regard to the engaging surfaces 9 and 10 in the annulargrooves 4 and 5. When being produced, the sealing lips 7, 8 extendbeyond the diameter defined by the annular grooves 4, 5, said diameterbeing indicated in FIG. I by dot-dash circle 11.

As will be seen from FIG. 2, when assembling the two parts 2,3 to beinterconnected, the protruding elastic sealing lips 7, 8 are in view ofthe lateral engagement pressed away laterally and snugly engage thesurfaces which will adapt itself to the minor unevenness of the sealingsurfaces.

9, 10. Any lateral offsetting of the two annular grooves 4, 5 iscompensated for by the elastic webs 6 which adapt themselves to therespective annular groove 4, 5. The plane along which both parts 2 and 3engage each other is indicated as joint 12.

In view of the described design of the sealing ring 1, it will beappreciated that in assembled condition between the webs 6 there will beformed four labyrinth chambers 13 while between the sealing lips 7, 8additional four labyrinth chambers 14 are formed which are distributeduniformly over the circumference so that each, on the side of part 2 aswell as on the side of part 3, five serially arranged labyrinth chambers13, 14 are provided which are available for sealing the joint 12.

FIGS. 3 and 4 illustrate a further embodiment of a sealing ring 1according to the invention. Those parts which correspond to the partsreferred to above in connection with FIGS. 1 and 2 have been designatedwith the same reference numerals but with the additional character b.The annular grooves in parts 2b and 3b are in this instance providedwith engaging surfaces 15 which are inclined at an angle of 45 withregard to the joint 12b. The engaging surfaces 15 are at the core of theannular groove interrupted by a depression 16. The sealing lips 17provided on the webs 6b are designed as continuous plane surfaces andare parallel to the engaging surfaces 15.

When assembling the parts 2b and 3b, as will be evident from FIG. 4, thesealing lips 17 are only partly deformed by the engaging surfaces 15,whereas the remaining parts 17a extend in a nearly non-deformed shapeinto the depressions l6 and form diagonally extending sealing surfaces.As a result thereof, during an elastic spring of the two parts 2b and3b, at least one sealing surface will each time become effective. Withthis design, on each side of the joint, only three labyrinth chambers13b each are formed.

FIGS. 5 and 6 show a modification of the sealing ring lb of FIGS. 3 and4 which is insertable in triangular annular grooves 4c and 5c of theparts 2c and 3c. The engaging surfaces 150 are likewise at an angle of45 inclined toward the joint 120 but are not interrupted. The webs 6care each provided with two sealing lips l8,

19 which form an acute angle with regard to their engaging surfaces lScso that during the assembly, in conformity with FIG. 6, similar to FIG.2 four labyrinth chambers 13c and 140 each are formed.

FIG. 7 shows the members 2, 3 to be interconnected in the form of twopipes having a sealing ring of the type shown in FIGS. 1 and 2interposed between adjacent end faces of said pipes.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular constructions shown in the drawing, butalso comprises any modifications within the scope of the appendedclaims.

What I claim is:

1. In combination with two parts to be sealingly interconnected,especially cylinder and cylinder head, and respectively provided withannular groove means arranged in the surfaces along which said two partsare to be sealingly connected to each other, said groove means being insubstantial alignment with each other, a profiled sealing ringcomprising an annular core and a plurality of annular webs extendingradially outwardly from said core respectively into the groove means ofsaid two parts and continuously tending to hold said groove means in onepart in alignment with the groove means in the other part to therebycenter said two parts with regard to each other, the outer ends of saidwebs forming sealing lips sealingly engaging portions of the gift? tlfliiot'fflilii fiiiitfiZftlf fitfii n faf 538 parts as caused bypressure and temperature variations, the outer end of each of said websbeing provided with two sealing lips extending in opposite directionswith regard to each other and the sides of each of said sealing lipsdefining with each other an acute angle.

2. A combination according to claim I, in which said sealing lips engagesaid wall portions plastically and elastically.

3. A combination according to claim 1, in which said groove means ineach of said parts includes oppositely inclined surfaces tapering in thedirection toward the bottom surface of the respective groove means andsealingly engaging the respective adjacent sealing lips.

4. A combination according to claim 3, in which said inclined surfacesform an angle of about 45 with the respective adjacent surface portionin which said groove means is provided.

5. A combination according to claim 3, in which the inclined surfaces ofsaid groove means in each of said parts are separated from each other byan annular groove.

6. In combination with two parts to be sealingly interconnected,especially cylinder and cylinder head, and respectively provided withannular groove means arranged in the surfaces along which said two partsare to be sealingly connected to each other, said groove means being insubstantial alignment with each other, a profiled sealing ringcomprising an annular core and a plurality of annular webs extendingradially outwardly from said core respectively into the groove means ofsaid two parts and continuously tending to hold said groove means in onepart in alignment with the groove means in the other part to therebycenter said two parts with regard to each other, the outer ends of saidwebs forming sealing lips sealingly engaging portions of the walls whichdefine said groove means and being elastic so as to follow axial andradial deformations of said two parts as caused by pressure andtemperature variations, the outer end of each of said webs beingprovided with two sealing lips extending in opposite directions withregard to each other, the sides of each of said sealing lips definingwith each other an acute angle, each two adjacent lips respectivelypertaining to two adjacent webs defining with the latter a labyrinth.

7. A combination according to claim 3, in which at least a portion ofthe radially outermost surfaces of said sealing lips is substantiallyparallel to said inclined surfaces and substantially perpendicular tothe axes of the pertaining webs.

8. A combination according to claim 7, in which only a portion of theradially outermost surfaces of said sealing means engages said inclinedsurfaces while another portion of said radially outermost surfacesextends in nearly undistorted manner in spaced relationship to the wallsof the respective adjacent groove means.

UNTTEE STATES PATENT oEETcE QERTIFICATE 0F CORRECHQN Patent No.3,682,489 Dated August 8, 1972 Inventor(s) Hans Fischer It is certifiedthat error appears in the above-identified patent and that said LettersPatent are'hereby corrected as shown below:

On the cover sheet insert [73] Assignee Maschinenfabrik Augsburg-NumbersAktiengesellschaft Signed and sealed this 19th day of December 1972.

(SEAL) Atteet:

EDWARD M.FLETC,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner ofPatent:

FORM PO-10 0 (10-69) USCOMM-DC 60376-P69 U.S. GOVERNMENT PRINTIN GOFFICE & I969 0-366-334,

1. In combination with two parts to be sealingly interconnected,especially cylinder and cylinder head, and respectively provided withannular groove means arranged in the surfaces along which said two partsare to be sealingly connected to each other, said groove means being insubstantial alignment with each other, a profiled sealing ringcomprising an annular core and a plurality of annular webs extendingradially outwardly from said core respectively into the groove means ofsaid two parts and continuously tending to hold said groove means in onepart in alignment with the groove means in the other part to therebycenter said two parts with regard to each other, the outer ends of saidwebs forming sealing lips sealingly engaging portions of the walls whichdefine said groove means and being elastic so as to follow axial andradial deformations of said two parts as caused by pressure andtemperature variations, the outer end of each of said webs beingprovided with two sealing lips extending in opposite directions withregard to each other and the sides of each of said sealing lips definingwith each other an acute angle.
 2. A combination according to claim 1,in which said sealing lips engage said wall portions plastically andelastically.
 3. A combination according to claim 1, in which said groovemeans in each of said parts includes oppositely inclined surfacestapering in the direction toward the bottom surface of the respectivegroove means and sealingly engaging the respective adjacent seaLinglips.
 4. A combination according to claim 3, in which said inclinedsurfaces form an angle of about 45* with the respective adjacent surfaceportion in which said groove means is provided.
 5. A combinationaccording to claim 3, in which the inclined surfaces of said groovemeans in each of said parts are separated from each other by an annulargroove.
 6. In combination with two parts to be sealingly interconnected,especially cylinder and cylinder head, and respectively provided withannular groove means arranged in the surfaces along which said two partsare to be sealingly connected to each other, said groove means being insubstantial alignment with each other, a profiled sealing ringcomprising an annular core and a plurality of annular webs extendingradially outwardly from said core respectively into the groove means ofsaid two parts and continuously tending to hold said groove means in onepart in alignment with the groove means in the other part to therebycenter said two parts with regard to each other, the outer ends of saidwebs forming sealing lips sealingly engaging portions of the walls whichdefine said groove means and being elastic so as to follow axial andradial deformations of said two parts as caused by pressure andtemperature variations, the outer end of each of said webs beingprovided with two sealing lips extending in opposite directions withregard to each other, the sides of each of said sealing lips definingwith each other an acute angle, each two adjacent lips respectivelypertaining to two adjacent webs defining with the latter a labyrinth. 7.A combination according to claim 3, in which at least a portion of theradially outermost surfaces of said sealing lips is substantiallyparallel to said inclined surfaces and substantially perpendicular tothe axes of the pertaining webs.
 8. A combination according to claim 7,in which only a portion of the radially outermost surfaces of saidsealing means engages said inclined surfaces while another portion ofsaid radially outermost surfaces extends in nearly undistorted manner inspaced relationship to the walls of the respective adjacent groovemeans.